Windblown Ripple 'Scylla'
These images were acquired by NASA's Mars Exploration Rover Opportunity using its panoramic camera on sol 644 (Nov. 15, 2005; upper two images) and its navigation camera on sol 645 (Nov. 16, 2005; lower image). The view looks towards the east, covering a large wind-blown ripple called "Scylla" other nearby ripples and patches of brighter rock strewn with dark cobbles. Panoramic camera bands L4 (601-nanometer wavelength), L5 (535 nanometers), and L6 (482 nanometers) correspond to red, green, and blue bands in the false-color image shown in the upper left. The blue-tinted colors associated with the scours and ripple crests are probably due to the presence of basaltic sands mixed with hematite-rich spherules. Color patterns on the larger ripple flanks are caused by different amounts of reddish dust. The larger ripple flanks have an intricate mixture of erosional scours and secondary ripples extending downward from the main ripple crests, suggesting that these ripples have most recently encountered a period of wind erosion and transport of their outer layers. For comparison, the same panoramic camera image is shown in the upper right, but in this case rendered as an approximately true-color composite.